Dim lights at 5000 rpm+

SLOroadster · Post by **SLOroadster** » Fri Oct 17, 2003 2:55 pm

I discovered an interesting thing a few weeks ago. I went for a drive a few weeks ago (at night) and as I went through about 5500 rpm in 3rd gear the headlights went really dim (about 6200 they might as well have been out). It did the same in 4th but not as much (I didn't have it wound as tight). Does anyone have any ideas on why this happens? I am running an 80 amp Chevy alternator so its producing plenty of power. It doesn't seem to do it in 1st or 2nd, and I will get arrested if I try in 5th.
Any thoughts?

Will

bedwyrbannog · Post by **bedwyrbannog** » Fri Oct 17, 2003 3:21 pm

Well my 2 cents.....sounds like the belt is sliping or at that rpm something is vibrating enough to cause a "short".

Doesn't the headlight relay vibrate enough at that rpm to lose contact?

Post by **spl310** » Fri Oct 17, 2003 3:39 pm

That is something that has plagued some Roadsters for years. Rallye even has an article about it in their tech insert (they may still be available - interesting reading) As I recall, the headlight relay is typically the culprit as previously suggested.

TR · Post by TR » Tue Oct 21, 2003 10:52 pm

Ya, the stock relays have a lot of mass to them and can be made to bounce with a mechanical input.

I don't know if isolating it from vibration is enough, make sure the case is grounded if you do try that route.

Otherwise, replace it with a few modern relays and all should be better...TR